1. Field of the Invention
The present invention relates to a battery using a polymer electrolyte including a polymer.
2. Description of the Related Art
In recent years, a large number of portable electronic devices such as camcorders, cellular phones and portable computers have emerged, and an attempt to reduce the size and the weight of them has been made. Accordingly, the development of batteries as portable power sources of the electronic devices, specifically secondary batteries have been actively promoted. Among the batteries, a lithium-ion secondary battery receives attention as a battery capable of obtaining a high energy density.
In such a lithium-ion secondary battery, a battery can made of metal such as aluminum (Al) or iron (Fe) is used as a package member. Recently, instead of the battery can made of metal, a laminate film is used as a package member so that the size, the weight and the profile of the battery are further reduced (for example, refer to Japanese Unexamined Patent Application Publication Nos. 2003-217674 and H6-150900).